Callier is Tuned in to Valuable Teaching Technique

FM Receivers Improve Signal-to-Noise Ratio for Children with Hearing Loss

Sept. 22, 2008

For more than 30 years, the UT Dallas Callier Center for Communication Disorders’ deaf education program has been using one of the most effective technologies to teach children with hearing loss: the personal FM receiver.

The personal FM receiver is an assistive listening device that improves the signal-to-noise ratio in the classroom. In other words, the receiver’s mission is to consistently keep the teacher’s voice – referred to as the signal – at a higher level than the surrounding noise.

The teachers in the deaf education program send voice signals to the individual receivers via FM radio frequency transmitters. To prevent the students from receiving signals from the wrong teacher, each classroom at Callier has a different frequency transmission.

The receiver’s purpose has remained unchanged, but the technology has advanced throughout the years. In the past, the system was hard-wired and required the students and teachers to plug their devices into a central receiver.

Today, the system is completely wireless, allowing the teachers and students to move freely about the classroom. The size of the devices has also decreased from large, body-worn receivers in harnesses, to tiny receivers that “plug-in” to behind-the-ear hearing aids.

“The personal FM receivers are a valuable tool for the deaf education program at Callier,” said Karen Clark, Callier Center’s education division director. “Since the severity of hearing loss is different for each child, the receivers and hearing aids can be programmed for an individual child. The newest receivers and transmitters automatically adapt to the noise level in the room, making sure the children can clearly hear the teacher over the noise.”

The Callier deaf education program is a collaboration with the Dallas Independent School District (DISD). There are currently 55 students with hearing loss enrolled in the program and using the personal FM receivers. The children either wear hearing aids, cochlear implants, or a combination of the two.

As part of its contract with the Callier Center, the DISD provides all of the equipment for the teachers and students. The equipment includes “school only” hearing aids and FM receivers worn by the students and FM transmitters worn by the teachers.

The Callier Center’s audiology department evaluates the equipment and makes recommendations to assist DISD in the selection of items that are most appropriate for students. A Callier Center audiologist, Dr. Nancy Hirsch, fits the FM equipment to each child and regularly monitors the equipment to make sure it is operating properly.

Dr. Hirsch is also responsible for the audiological services provided to each of the students at Callier, as well as all of the students in the Dallas Regional Day School Program for the Deaf. She coordinates the activities of three Callier Center audiology externs - fourth year students in the School of Behavioral and Brain Sciences’ Doctor of Audiology Program - who assist her in covering the entire district’s program through Callier’s contract with the DISD.

The Callier Center audiology department also provides similar contact services for the Plano Regional Day School Program for the Deaf through the Callier Center’s Richardson location on the UT Dallas campus. Those services are managed by Dr. Laura Veazey, with the assistance of one audiology extern.

“We are proud of our role in working with the DISD in this collaborative effort, as well as our role in providing treatment options for children with permanent hearing loss in other districts,” said Dr. Lee Wilson, head of the audiology clinical program at the Callier Center.